Puncturing pin for fire extinguisher seals



Nov. 16, 1954 c. K. HUTHSING PUNCTURING PIN FOR FIRE EXT INGUISHER SEALS Filed June 8 1951 INVENTOR.

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United States Patent 1 2,694,456 PUNCTURING PIN FOR FIRE EXTINGUISHER SEALS Charles K. Huthsing, Los Angeles, Calif. Application June 8, 1951, Serial No. 230,606 2 Claims. (Cl. 169-31) This invention relates to a puncturing pin for fire extinguisher seals.

Several types of fire extinguishers include an outer casing having an opening with a removable head which supports a pressurized gas bottle within said casing. The bottle is provided with a seal which can be ruptured or punctured to permit the escape of gas from the bottle into the surrounding tank or container and thereby force the fire extinguishing material from the container. Gas under pressure, such as carbon dioxide has been used in extinguishers for expelling materials such as water, liquid chemicals and dry, powdered chemicals.

The gas bottle seal is, in many cases, broken by a puncturing pin which is manually forced through the seal. This pin is frequently in the form of a smoothly tapered element. The result is that the tapered pin, if held in its seal-piercing position will nearly completely fill the opening which it has made in the seal. Consequently gas cannot escape readily from the pressure bottle in which it is stored.

The present invention contemplates the provisioning of a puncturing pin whose cross sectional mass is less than the total cross sectional area encompassed by the pin so that the puncturing pin will produce a hole in the seal which is considerably larger than the solid area of the pin itself. This permits the gas to escape readily even though the pin may not be withdrawn from the seal.

The above and other objects will more fully appear from the following description in connection with the accompanying drawing.

Fig. 1 is a fragmentary vertical sectional view through the upper portion of a fire extinguisher embodying my invention;

Fig. 2 is a perspective view of the puncturing pin per se;

Fig. 3 is an enlarged end view of the pin looking in the direction of the arrow III.

Fig. 4 is a section taken on the line IVIV of Fig. 1.

In Fig. 1 there is shown the top portion of a fire extinguisher tank 6. It has an upwardly extending flange 8 which defines a rather large opening in the top of the tank. The outer wall of the flange 8 is threaded to receive a threaded collar 10 which is adapted to hold the flanged edge 12 of a head casting 14 against the upper edge of the tank flange 8. A suitable O-ring seal 16 is carried by the head 14 and is in sealing contact with the inner wall of flange 8.

The head casting 14 is provided with a downwardly disposed central boss 18 of cylindrical form. The inner wall of the boss 18 is threaded to receive a threaded collar 20 which forms part of an adapter 22. The lower portion of the adapter is provided with a threaded taper 24 which fits into the upper threaded end of a pressure bottle 26 adapted to hold a gas such as carbon dioxide. The adapter 22 has a central passage 28 extending vertically therethrough.

The threaded collar 20 on the adapter 22 is internally threaded to, in turn, receive a threaded collar 30 which holds a rupturable seal 32 in a manner well known in the art and for that reason not specifically described herein. When the seal 32 is broken, gas can escape through the adapter passage 28 and the innermost threaded flange 30 to a chamber 34 in the head casting 14. Said chamber 34 communicates with a port 36 which, in turn, is in flow communication with a gas tube 38 leading to a lower portion of the extinguisher tank 6. The escaping gas under pressure forces liquid or powdered extinguishing material through an outlet tube 40 and a passage 42 in the head 14 to a hose 44 through which the extinguishing material is played on a fire.

The head casting 14 has a cylindrical bore 46 whose lower portion is enlarged as at 48. The bore portion 46 slidably receives a cylindrical stem 50 on whose lower end is a piston structure 52 having a packing ring 54. Extending from the lower end of the piston 52 is a reduced stem 56 which supports a puncturing pin tip 58. This tip is shown to be of spiral shape and is conveniently formed by twisting the relatively thin, flat metal of the tip through The lower puncturing edge 60 of the tip may be oblique as best shown in Fig. l and it may be sharpened if desired, although this is not thought to be necessary.

The upper end of the cylindrical stem 50 is provided with an aperture 62 to receive a pin 64 which extends between a pair of spaced lugs 66 on a hand lever 68. The hand lever is connected by a pivoted pin 70 to a lug 72 forming an upward extension of the head casting 14. A compression spring 74 has its lower end lying in a socket 76 in the head 14. The upper end of the spring lies about a projection 78 formed on the under side of the hand lever 68. I

The head casting 14 has a supporting handle 80 connected thereto by pins 82.

In use, the extinguisher is picked up by the handle 80, pressure being applied to the hand lever 68 by simultaneously gripping it and the handle. This forces the non-rotating cylindrical stem 50, the piston 52 and the puncturing element 58 downwardly. The two extreme positions of the puncturing pin element are shown in full and broken lines in Fig. 1. It will be seen that the puncturing pin will pierce and circularly cut the seal 32 and permit gas to escape from the bottle 26 in the manner described above.

By reason of the non-rotatable and spiralled puncturing pin element 58, the seal 32 will have an opening formed therein of greater area than the cross sectional area of the spiral pin. This leaves a considerable amount of free opening through which the gas can escape even though the puncturing element is held in the broken line position shown in Fig. l.

Considerable difliculty has been encountered with ordinary smoothly tapered pin constructions but tests have shown that my puncturing pin insures the desired free escape of gas from the bottle 26.

In Fig. 4 there is illustrated a locking arrangement for securing the threadedly interconnected central boss 18 of the head casting 14 and the collar 20 on the adapter 22. The boss 18 is hexagonal, as shown in Fig. 4. It is bored through opposite sides to receive the arms 90 of a locking pin 92. The arms 90 are joined by a loop 94 which is anchored by a chain 96 to the boss 18, as shown in Fig. 1. The locking pin arms 90 lie at opposite side portions of the collar 20 beneath the external threads on the collar and thus prevent the two parts from being unscrewed until the locking pin 92 is withdrawn. The locking pin itself is held in position by the proximity of the loop 94 to the flange 8 which defines the main tank opening.

It will, of course, be understood that various changes in the form and details can be made without departing from the scope of the invention.

1 claim:

1. In a fire extinguisher having a sealed gas bottle therein with a rupturable seal, a non-rotatable plunger slidably carried by the extinguisher and movable through the area of the seal, the plunger being relatively flat and having a spiral shape to create a break in the seal larger than the cross sectional area of the body of the plunger.

2. The structure in claim 1, and the leading edge of the plunger being oblique.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,715,347 Badger June 4, 1929 1,979,390 Jacobs Nov. 6, 1934 2,084,339 Hanley et al. June 22, 1937 2,105,487 Lozon .'Jan. 18, 1938 2,219,096 Tomkin Oct. 22, 1940 2,541,554 Smith Feb. 13, 1951 2,548,157 Henshaw Apr. 10, 1951 

